Stabilizer for organic borate salts and photosensitive composition containing the same

ABSTRACT

A stabilizer for thermally stabilizing an organic borate salt represented by formula (1) is disclosed, comprising a compound having one or two nitrogen-containing 5- or 6-membered heterocyclic ring having a double bond within the ring, a compound having a primary, secondary or tertiary amino group, or a compound having a thiol group. Also disclosed are a photosensitive composition comprising the stabilizer, an organic borate salt and if desired, a sensitizing dye or further a bisimidazole compound; a polymerizable composition comprising the photosensitive composition having added thereto at least one monomer having one or more ethylenically unsaturated bond and if desired, a high molecular polymer or further a pigment; and a colored pattern formed by using the polymerizable composition.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a stabilizer for preventing thethermal decomposition or reaction of an organic borate salt, aphotosensitive composition comprising the stabilizer and an organicborate salt, a polymerizable composition comprising the photosensitivecomposition having added thereto a monomer having an ethylenicallyunsaturated bond, which has excellent heat stability and aging stabilityand is prevented from impairment of the polymerization reactivity, aphotopolymerization initiator capable of exhibiting goodpolymerizability even in the presence of oxygen, and a polymerizablecomposition containing the photopolymerization initiator.

[0003] This application is based on Japanese Patent Applications Nos.Hei 9-229376 and Hei 10-199080, the contents of which are incorporatedherein by reference.

[0004] 2. Description of Related Art

[0005] A large number of studies have been made on organic borate saltsas an important constituent element of a photopolymerizable composition.Examples thereof include an organic boron compound anion salt of anorganic cationic dye (see, JP-A-62-143044 (the term “JP-A” as usedherein means an “unexamined published Japanese patent application”),JP-A-64-13141 and JP-A-2-3052) and a system of separately adding anorganic cationic dye and an organic borate salt but not adding these inthe form of a complex (see, JP-A-2-4804 and JP-A-5-194619). In any ofthese publications, a photo-polymerizable composition having highphotosensitivity obtained by adding a monomer having an ethylenicallyunsaturated bond to the organic borate salt, is disclosed.

[0006] However, these photopolymerizable compositions containing anorganic borate salt are not sufficiently high in the heat stability. Forexample, in a photopolymerizable composition containing an organicborate salt, the organic borate salt gradually decomposes at 0° C. orhigher and the decomposition is further accelerated at highertemperatures. As a result of decomposition of the organic borate salt,the photopolymerizable composition is reduced in thephotopolymerizability and cannot be cured even with a sufficiently largeamount of exposure.

[0007] Not only the decomposition of the organic borate salt in thephotopolymerizable composition but also unintended polymerizationreaction proceed in a dark place. Thus, the photopolymerizablecomposition is polymerized before exposure and cannot be used any more.Furthermore, as the acidity of the photopolymerizable compositionincreases, the organic borate salt is extremely reduced in the heatstability and seriously decomposes during the storage.

[0008] In order to overcome these problems, attempts have heretoforebeen made to achieve stabilization by controlling the structure of theorganic borate salt, the structure or composition of the sensitizer ormonomer having an ethylenically unsaturated bond, or the neutralizationof the acidity of the composition. However, satisfactory effects havenot yet been achieved.

[0009] With respect to the photopolymerizable composition containing amonomer having an ethylenically unsaturated bond and as thephotopolymerization initiator system, a titanocene compound and asensitizer, a photopolymerizable composition further containing aheterocyclic thiol compound so as to achieve stabilization of thetitanocene compound is known (see, JP-A-9-5996). However, the effect ofimproving the stability of the titanocene compound is not yet satisfied.

[0010] On the other hand, radiation polymerization using aradiation-sensitive polymerization initiator is being used in variousfields such as semiconductor relative, printing ink, printing plate,coating, adhesion and liquid crystal display. The radiation includeshigh energy radiation such as electron beam and X ray, and low energyradiation such as ultraviolet ray, visible ray and infrared ray, and theradiation is applied by means of a device (lamp) emitting respectiverays according to the use purposes. The high energy radiation has a highpolymerization initiating capability because of its high energy but isdisadvantageous in the complicated apparatus or process necessarytherefor, the high use energy and the adverse effects on the environmentor an operator. However, due to tendency to use a photopolymerizationinitiator which generates radicals by light of a low energy radiationsuch as ultraviolet ray, visible ray or infrared ray, the dangerous highenergy radiation is less required. In particular, the photoradicalpolymerization initiator can polymerize vinyl-base monomers with lowenergy to thereby promise high sensitivity and high-speed processing andaccordingly, is being used very often.

[0011] However, it is known that if the radical polymerization isperformed in the presence of oxygen, the radicals generated combine withthe oxygen to convert into a relatively stable peroxy radicals nothaving the polymerization initiating capability, whereby thepolymerization is inhibited and insufficient polymerization results.This phenomenon is particularly outstanding on the surface of thephotopolymerizable composition in contact with air or in the case of athin film.

[0012] To overcome this problem, a method of blocking oxygen by formingan oxygen-blocking film on the surface of the polymerizable compositionso as to prevent the effects of oxygen, a method of performing thepolymerization by placing the polymerization material as a whole in anitrogen atmosphere, a method of adding a large amount of aphotopolymerization initiator to maintain the sensitivity, a method ofadding a tertiary amino compound and generating active radicals fromstabilized peroxy radicals to allow the polymerization to proceed, and amethod of using a photocationic polymerization initiator and not relyingon radicals have heretofore proposed.

[0013] However, the above-described methods for overcoming the problemof polymerization inhibition due to oxygen are disadvantageous in thatthe costs of raw material, process and equipment are greatly increased,the sensitivity is low, the productivity decreases due to complicatedprocesses, and stability or odor of the polymerizable composition or theproduct after polymerization is another problem. Accordingly, themethods are limited in the use field or usage.

SUMMARY OF THE INVENTION

[0014] The present invention has been made to satisfy the requirementsfor solving the above-described problems.

[0015] A first object of the present invention is to provide anexcellent stabilizer capable of imparting heat stability to the organicborate salt.

[0016] A second object of the present invention is to provide aphotosensitive composition comprising this stabilizer and an organicborate salt or comprising this stabilizer, an organic borate salt and asensitizing dye.

[0017] A third object of the present invention is to provide apolymerizable composition comprising the above-described photosensitivecomposition having added thereto a monomer having an ethylenicallyunsaturated bond, which is excellent in the heat stability and agingstability and is prevented from impairment of the polymerizationreactivity.

[0018] A fourth object of the present invention is to provide ahigh-sensitivity photosensitive composition capable of efficientlyinitiating photopolymerization even in the presence of oxygen.

[0019] As a result of extensive investigations to solve the problems,the present inventors have found that the above-described objects can beattained by using a stabilizer having a specific molecular structure,which not only remarkably improves the stability of the organic boratesalt represented by formula (1) having low heat stability but alsoprevents impairment of the photoreactivity of the polymerizablecomposition containing the organic borate salt, and further that thephotosensitive composition comprising, out of stabilizers of the presentinvention, a compound having one or two nitrogen-containing 5- or6-membered heterocyclic ring having a double bond within the ring or acompound having a thiol group and an organic borate salt represented byformula (1) is a high-sensitivity photosensitive composition capable ofefficiently initiating photopolymerization even in the presence ofoxygen and a photopolymerizable composition comprising thisphotosensitive composition has high sensitivity even in the presence ofoxygen. The present invention has been accomplished based on thesefindings.

[0020] More specifically, the invention provides:

[0021] 1) A stabilizer for thermally stabilizing an organic borate saltrepresented by formula (1), comprising a compound having one or twonitrogen-containing 5- or 6-membered heterocyclic ring having a doublebond within the ring, a compound having a primary, secondary or tertiaryamino group, or a compound having a thiol group:

[0022] (1)

[0023] (wherein R₁, R₂, R₃ and R₄ each independently represents an alkylgroup, an aryl group, an allyl group, an aralkyl group, an alkenylgroup, an alkynyl group, an alkoxy group, a silyl group, an alicyclicgroup, a heterocyclic group,a hydrogen atom or a halogen atom, and Z⁺represents a quaternary ammonium cation, a quaternary pyridinium cation,a quaternary quinolinium cation, a phosphonium cation, a sulfoniumcation, an oxosulfonium cation, an oxonium cation, an iodonium cation, ametal cation or a cationic dye having absorption in the ultravioletand/or visible ray region).

[0024] 2) A stabilizer for thermally stabilizing an organic borate saltrepresented by formula (1), comprising a compound having one or twonitrogen-containing 5- or 6-membered heterocyclic ring having a doublebond within the ring, a compound having a primary, secondary or tertiaryamino group, or a compound having a thiol group:

[0025] (wherein R₁, R₂, R₃ and R₄ each independently represents an alkylgroup, an aryl group, an allyl group, an aralkyl group, an alkenylgroup, an alkynyl group, an alkoxy group, a silyl group, a heterocyclicgroup, a hydrogen atom or a halogen atom, and Z⁺ represents a quaternaryammonium cation, a quaternary pyridinium cation, a quaternaryquinolinium cation, a phosphonium cation, a sulfonium cation, an oxoniumcation, an iodonium cation, a metal cation or a cationic dye havingabsorption in the ultraviolet and/or visible ray region).

[0026] 3) The stabilizer as described in 1) and 2) above, wherein thecompound having one or two nitrogen-containing 5-or 6-memberedheterocyclic ring having a double bond within the ring is a compoundhaving one or more heterocyclic ring selected from triazole, pyridine,pyrimidine, pyrazole, piperazine, tetrazole, acridine, adenine,benzothiazole, triazine, thiadiazole, imidazole, benzimidazole,thiazoline, indoline and imidazoline.

[0027] 4) The stabilizer as described in 1) and 2) above, wherein thecompound having a primary, secondary or tertiary amino group is an aminerepresented by formula (2):

R₅R₆R₇N  (2)

[0028] (wherein R₅, R₆ and R₇ each independently represents hydrogen, analkyl group, an aryl group, an allyl group, an aralkyl group, an alkenylgroup, an alkynyl group, a heterocyclic group or an alicyclic group,provided that at least one of -R₅ R₆ and R, is not hydrogen. Two orthree of R₅, R₆ and R₇ may be combined to form a cyclic structure).

[0029] 5) The stabilizer as described in 1) or 2) above, wherein thecompound having a thiol group is a thiol represented by formula (3):

R₈—SX (3)

[0030] (wherein R₈ represents an alkyl group, an aryl group, an aralkylgroup, an alkenyl group, an alkynyl group, an alicyclic group or aheterocyclic group, and X represents sodium or hydrogen).

[0031] 6) A photosensitive composition comprising the stabilizerdescribed in 1) or 2) above and an organic borate salt represented byformula (1).

[0032] 7) A photosensitive composition comprising the stabilizerdescribed in 1) or 2) above, an organic borate salt represented byformula (1) and a sensitizing dye.

[0033] 8) The photosensitive composition as described in 6) and 7)above, wherein the stabilizer is a compound having one or twonitrogen-containing 5- or 6-membered heterocyclic ring having a doublebond within the ring or a compound having a thiol group.

[0034] 9) The photosensitive composition as described in 8) above,wherein the stabilizer is at least one selected from mercaptoimidazole,mercaptobenzimidazole, mercaptobenzothiazole, triazinetrithiol,mercaptotriazole, mercaptothiazoline, mercaptothiadiazole andmercaptotetrazole.

[0035] 10) The photosensitive composition as described in 8) and 9)above, which further contains a bisimidazole compound.

[0036] 11) A polymerizable composition capable of polymerization bylight or heat, comprising the photosensitive composition described inany one of 6) to 10) above having added thereto at least one monomerhaving one or more ethylenically unsaturated bond.

[0037] 12) A polymerizable composition comprising the photosensitivecomposition described in any one of 6) to 10) above having added theretoat least one monomer having one or more ethylenically unsaturated bondand a high molecular polymer.

[0038] 13) A polymerizable composition comprising the photosensitivecomposition described in any one of 6) to 10) above having added theretoat least one monomer having one or more ethylenically unsaturated bond,a pigment and a high molecular polymer.

[0039] 14) The polymerizable composition as described in 12) and 13)above, wherein the high molecular polymer has an acid value of from 20to 800 mgKOH/g.

[0040] 15) A colored pattern formed on a substrate using a polymerizablecomposition described in any one of 11) to 14) above.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] Representative examples of the stabilizer comprising a compoundhaving one or two nitrogen-containing 5- or 6-membered heterocyclic ringhaving a double bond within the ring of the present invention includecompounds having a heterocyclic ring such as triazole, pyridine,pyrimidine, pyrazole, piperazine, tetrazole, acridine, adenine,benzothiazole, triazine, thiadiazole, imidazole, benzimidazole,thiazoline, indoline or imidazoline.

[0042] Specific examples of this stabilizer of the present inventioninclude 1,2,4-triazole, 3-amino-1,2,4-triazole (Compound 1),mercapto-1,2,4-triazole (Compound 2), 3-amino-5-carboxy-1,2,4-triazole,2,6-dimethylolpyridine (Compound 3), 4-dimethylaminopyridine (Compound4), mercaptopyrimidine (Compound 5), 2-aminonaphtho[1,2]thiazole,benzothiazole, 2-mercaptobenzothiazole (Compound 6),2-aminobenzothiazole, 2-amino-1,3,4-thiadiazole (Compound 7),2,5-dimercapto-1,3,4-thiadiazole, 5-amino-1,3,4-thiadiazole-2-thiol,2,4,6-triamino-1,3,5-triazine (Compound 8),1,3,5-triazine-2,4,6-trithiol, 3-mercapto-4-methyl-4H-1,2,4-triazole,5-mercapto-1-methyltetrazole, 1-phenyl-5-mercapto-lH-tetrazole,5-methyl-1,3,4-thiadiazole-2-thiol, mercaptothiazole, mercaptotetrazole,2-mercaptobenzoxazole, 2-mercaptobenzothiazole sodium salt,furfurylmercaptan, mercaptoimidazole, 1-acetylimidazole,2-mercapto-1-methylimidzole (Compound 9), N-methylimidazole (Compound10), 1,2-dimethylimidazole, 2-aminobenzimidazole,2-mercaptobenzimidazole (Compound 11), 2-mercaptothiazoline (Table 1:Compound 12), acridine, 1-(2-aminoethyl)piperazine, 5-amino-1Htetrazole, 3,5-dimethylpyrazole and phenothiazine.

[0043] Examples of the stabilizer comprising an amine represented byformula (2) include compounds where in formula (2), R₅, R₆ and R₇ eachindependently represents hydrogen, an alkyl group, an allyl group, anaryl group, an aralkyl group, an alkenyl group, an alkynyl group, analicyclic group or a heterocyclic group, or two or three of R₅, R₆ andR₇ are combined to form a cyclic structure (provided that at least oneof R₅, R₆ and R₇ is selected from those other than hydrogen).

[0044] More specifically, the alkyl group represented by R₅, R₆ or R₇ isa substituted or unsubstituted, linear or branched alkyl group havingfrom 1 to 20 carbon atoms and examples thereof include a methyl group,an ethyl group, a propyl group, an isopropyl group, a butyl group, anisobutyl group, a sec-butyl group, a pentyl group, a hexyl group, aheptyl group, an octyl group, a 3-methoxypropyl group, a 4-chlorobutylgroup and a 2-diethylaminoethyl group.

[0045] The allyl group is a substituted or unsubstituted allyl group andspecific examples thereof include a 2-methylallyl group and a3-chloroallyl group.

[0046] The aryl group is a substituted or unsubstituted aryl group andspecific examples thereof include a phenyl group, a tolyl group, a xylylgroup, a 4-ethylphenyl group, a 4-tertbutylphenyl group, a4-methoxyphenyl group, a 4-diethylaminophenyl group, a 2-methylphenylgroup, a 2-methoxyphenyl group, a naphthyl group and a 4-methylnaphthylgroup.

[0047] The aralkyl group is a substituted or unsubstituted aralkyl groupand specific examples thereof include a benzyl group, a phenethyl group,a propiophenyl group, an α-naphthylmethyl group, a β-naphthylmethylgroup and p-methoxybenzyl group.

[0048] The alkenyl group is a substituted or unsubstituted alkenyl grouppreferably having from 2 to 12 carbon atoms and specific examplesthereof include a vinyl group, a propenyl group, a butenyl group, apentenyl group, a hexenyl group, a heptenyl group, an octenyl group, adodecinyl group and a prenyl group.

[0049] The alkynyl group is a substituted or unsubstituted alkynyl grouppreferably having from 4 to 12 carbon atoms and specific examplesthereof include a butynyl group, a pentynyl group, a hexynyl group andan octynyl group.

[0050] The alicyclic group is a substituted or unsubstituted alicyclicgroup and specific examples thereof include a cyclohexyl group, a4-methylcyclohexyl group, a cyclopentyl group and a cycloheptyl group.

[0051] The heterocyclic group is a substituted or unsubstitutedheterocyclic group and specific examples thereof include a pyridylgroup, a quinolyl group, a methylpyridyl group, an indolyl group, animidazolyl group and a triazyl group.

[0052] Specific examples of this stabilizer include hexylamine,di-n-butylamine (Compound 14), dipropylamine, triethylamine,diethyldiamine, N,N,N′,N′-tetraethylmethylenediamine (Compound 15),2-ethylaminoethanol, 3-diethylamino-1-propanol, tributylamine, aniline,naphthylamine, benzylamine, diallylamine, phenylenediamine,octenylamine, cyclohexylamine 3-aminopyridine, aminoimidazole,hexamethylenetetramine, N-methylmorpholine (Compound 13) andtriethylenediamine (Compound 16).

[0053] The stabilizer comprising a thiol represented by formula (3) ofthe present invention a compound where an alkyl group, an aryl group, anaralkyl group, an alkenyl group, an alkynyl group, an alicyclic group ora heterocyclic group is bonded with a thiol group or a sodium saltthereof and examples thereof include the compounds where in formula (3),R₈ is an alkyl group, an allyl group, an aralkyl group, an alkenylgroup, an alicyclic group or a heterocyclic group, and X is sodium orhydrogen.

[0054] More specifically, the alkyl group is a substituted orunsubstituted, linear or branched alkyl group having from 1 to 20 carbonatoms and examples thereof include a methyl group, an ethyl group, apropyl group, an isopropyl group, a butyl group, an isobutyl group, asec-butyl group, a pentyl group, a hexyl group, a heptyl group, an octylgroup, a 3-methoxypropyl group, a 4-chlorobutyl group and a2-diethylaminoethyl group.

[0055] The aryl group is a substituted or unsubstituted aryl group andspecific examples thereof include a phenyl group, a tolyl group, a xylylgroup, a 4-ethylphenyl group, a 4-tertbutylphenyl group, a4-methoxyphenyl group, a 4-diethylaminophenyl group, a 2-methylphenylgroup, a 2-methoxyphenyl group, a naphthyl group and a 4-methylnaphthylgroup.

[0056] The aralkyl group is a substituted or unsubstituted aralkyl groupand specific examples thereof include a benzyl group, a phenethyl group,a propiophenyl group, an α-naphthylmethyl group, a β-naphthylmethylgroup and a p-methoxybenzyl group.

[0057] The alkenyl group is a substituted or unsubstituted alkenyl grouppreferably having from 2 to 12 carbon atoms and specific examplesthereof include a vinyl group, a propenyl group, a butenyl group, apentenyl group, a hexenyl group, a heptenyl group, an octenyl group, adodecinyl group and a prenyl group.

[0058] The alkynyl group is a substituted or unsubstituted alkynyl grouppreferably having from 4 to 12 carbon atoms and specific examplesthereof include a butynyl group, a pentynyl group, a hexynyl group andan octynyl group.

[0059] The alicyclic group is a substituted or unsubstituted alicyclicgroup and specific examples thereof include a cyclohexyl group, a4-methylcyclohexyl group, a cyclopentyl group and a cycloheptyl group.

[0060] The heterocyclic group is a substituted or unsubstitutedheterocyclic group and specific examples thereof include a pyridylgroup, a quinolyl group, a methyl-pyridyl group, an indolyl group, animidazolyl group and a triazyl group.

[0061] Specific examples of this stabilizer include propanethiol,octanethiol, decanethiol (Compound 17), dodecanethiol (Compound 18),benzenethiol, toluenethiol, naphthalenethiol, mercaptoethanol,ethyl-2-mercaptoacetate, cyclopentanethiol, 2-benzimidazolethiol and1,2,4-triazol-3-thiol.

[0062] Among the above-described stabilizers, heterocyclic compoundscontaining a tertiary nitrogen atom within the ring are particularlyeffective for the thermal stabilization.

[0063] Specific examples of the anion moiety in the organic borate saltrepresented by formula (1) for use in the present invention includen-butyltriphenyl borate, n-octyltriphenyl borate, n-dodecyltriphenylborate, sec-butyltriphenyl borate, tert-butyltriphenyl borate,benzyltriphenyl borate, n-butyltrianisyl borate, ethyltributyl borate,phenethyltrimethyl borate, phenyltruisobutyl borate,n-pentyltri(4methoxyphenyl) borate, n-butyltri (6-methoxy-2-naphthyl)borate, methyltri (1-naphthyl) borate, n-butyltrinaphthyl borate,n-butyltri (4-methylnaphthyl)borate and ethyltriacenaphthyl borate.

[0064] Specific examples of the cation moiety in the organic borate saltrepresented by formula (1) for use in the present invention includetetramethylammonium, tetraethylammonium, tetra-n-butylammonium,tetra-n-octylammonium, methylquinolinium, methylpyridinium,tetramethylphosphonium, tetra-n-butylphosphonium, trimethylsulfonium,triphenylsulfonium, trimethyloxosulfonium, diphenyliodonium,di(4-tert-butyl-phenyl) iodonium, (2-hydroxyethyl)trimethylammonium,lithium, potassium, sodium, cyanine dye cation, azomethine dye cation,xanthene dye cation and leuco dye cation.

[0065] Organic borate salts consist of the above-described anion moietyand cation moiety may be used in the present invention, however, thepresent invention is by no means limited thereto.

[0066] In the present invention, the method for adding the stabilizer ofthe present invention to the organic borate salt represented by formula(1) is not particularly limited, however, the stabilizer of the presentinvention is preferably dissolved in a solvent in which the organicborate salt is dissolved, because stability against heat and aging canbe obtained. When these are dissolved under heating at a temperature offrom room temperature to the boiling point of the solvent or atemperature lower than the melting point or decomposition point of theorganic borate salt itself, whichever is lower, the organic borate saltis prevented from the decomposition and higher stability against heatand aging can be obtained as compared with the case where the stabilizerof the present invention is not added.

[0067] The stabilizer of the present invention is considered to exertthe stabilizing effect based on the interaction or the like during thethermal reaction of the organic borate salt represented by formula (1).This is also inferred from the fact that a sufficiently high effect isbrought out even when the amount of the stabilizer of the presentinvention added is very small on the basis of the organic borate saltand the effect is higher than the effect attained only by mereneutralization of the acidic substance within the system.

[0068] The stabilizer of the present invention also has a property ofnot inhibiting useful reaction intended, such as photoreaction, evenwhen it is added in an excess amount.

[0069] By adding the stabilizer of the present invention, the organicborate salt can have heat stability. The organic borate salt is impartedwith heat stability and aging stability in the process where the mixtureof a composition having added thereto the stabilizer of the presentinvention is applied continuously or using, if desired, one or moremeans of dissolution, dispersion, kneading, emulsification and the liketo a medium or solvent.

[0070] As described above, the stabilizer of the present invention iseffective as a stabilizer of an organic borate salt and by combining itwith an organic borate salt, the resulting composition can be used as aphotosensitive composition.

[0071] The ratio of the stabilizer of the present invention to theorganic borate salt used may be freely selected, however, the stabilizeris preferably used in an amount of from 10 to 500 wt %, more preferablyfrom 50 to 200 wt %, based on the organic borate salt. Two or morestabilizers and two or more organic borate salts may be used.

[0072] The organic borate salt is usually accelerated to decompose byheat if a sensitizing dye is present, however, in the compositioncomprising an organic borate salt having added thereto the stabilizer ofthe present invention, the organic borate salt is prevented from thethermal decomposition or reaction even when a sensitizing dye havinglight absorbing power is added to the composition. Accordingly, changeor decomposition of the sensitizing dye due to the reaction between thesensitizing dye and the organic borate salt is difficult to occur ascompared with the case where the stabilizer of the present invention isabsent.

[0073] The term “sensitizing dye” as used in the present invention meansa cationic dye such as cyanine, xanthene, oxazine, thiazine,diarylmethane, triarylmethane and pyrylium, or an electrically neutraldye, namely, an organic dye not comprising a counter ion but containing+∘− due to resonance within the same molecule, such as merocyanine,coumarin, indigo, aromatic amine, phthalocyanine, azo and quinone-typesensitizing dyes.

[0074] In the case of a cationic dye, the counter anion may be anyanion, for example, a halogen anion such as chloride, bromide or iodideanion, a benzenesulfonate anion, a p-toluenesulfonate anion, amethanesulfonate anion, an organic borate anion, a BF₄ anion, a PF₆anion or a perchlorate anion.

[0075] Specific examples of the cationic dye as the sensitizing dyeinclude Crystal Violet (CI42555), Methyl Violet (CI42535), MalachiteGreen (CI42000), Fuchsin (CI42510), Crystal Violet-Carbinol Base(CI42555:1), Parafuchsin (CI42500), Rhodamine B (CI45170), Victoria BlueB (CI44045), Victoria Pure Blue BOH (CI42595), Brilliant Green(CI42040), Night Blue BX (CI51185), Neutral Red (CI50040), Basic Orange21 (CI48035), Basic Yellow 11, Basic Yellow 21, Basic Yellow 22, BasicRed 1 (CI45160), Basic Red 5 (CI50040), Basic Red 13 (CI48015), BasicViolet 7 (CI48020), Basic Violet 11 (CI45175), p-toluenesulfonate ornaphthalenesulfonate of Crystal Violet, p-toluenesulfonate orperchlorate of Victoria Blue B, p-toluenesulfonate or BF₄ salt of BasicOrange 21, and naphthalenesulfonate or PF₆ salt of Basic Red 5.

[0076] Specific examples of the electrically neutral dye include3-allyl-1-carboxymethyl-5-[2-(3-ethyl-2(3H)benzoxazolylidene]-2-thiohydantoin,4-[2-(3-ethyl-2(3H)benzothiazolylidene)ethylidene]-3-phenyl-2-isooxazolin-5-one,3-(2-benzothiazolyl)-7-(diethylamino)coumarin,3-(2-benzimidazolyl)-7-(diethylamino)coumarin, ethyl2,3,6,7-tetrahydro-11-oxo-1H,5H,11H-[l]benzopyrano[6,7,8-ij]quinalizine-10-carboxylate,N,N′-diethylindigo, thioxoindigo, 2-dimethyl-aminoanthraquinone,4-hydroxyazobenzene and 4-phenylamino-4′- nitroazobenzne.

[0077] The sensitizing dye which can be freely combined with an organicborate salt and the stabilizer to obtain a photosensitive composition isadded in an amount of from 1 to 100 wt %, preferably from 5 to 30 wt %,based on the photosensitive composition. If the concentration of thesensitizing dye is less than the this range, absorption of light isreduced and the light energy cannot be used efficiently, whereas if theconcentration greatly exceeds the above-described range, light isexcessively absorbed by the dye, as a result, the light intensityextremely decreases in the area farther from the surface irradiated bylight and sufficiently high photosensitivity cannot be ensured in thedepth. The photosensitive composition of the present invention canexhibit efficient photoreaction even when two or more of theabove-described sensitizing dyes are present together and due to theaction of the stabilizer of the present invention, the composition canhave stability.

[0078] The stabilizer of the present invention exerts the effect ofpreventing the thermal decomposition or reaction of an organic boratesalt even in a composition comprising the stabilizer of the presentinvention and an organic borate salt or in a polymerizable compositionobtained by adding at least one compound having one or moreaddition-polymerizable ethylenically unsaturated bond to a compositioncontaining the stabilizer of the present invention, an organic boratesalt and a sensitizing dye.

[0079] In the state where the stabilizer is absent, the organic boratesalt thermally decomposes or reacts, the active species generated causeschain reaction of the double bonds of the compound having anethylenically unsaturated bond, and unintended addition polymerizationmay proceed. However, in the polymerizable composition containing thestabilizer of the present invention, the organic borate salt isprevented from the thermal decomposition or reaction and therebyunintended thermal polymerization reaction during the storage isinhibited, hence, the composition can have aging stability.

[0080] A photosensitive composition can be obtained from a compoundhaving one or two nitrogen-containing heterocyclic ring having a doublebond within the ring or a compound having a thiol group represented byformula (3), out of the stabilizers of the present invention, and anorganic borate salt represented by formula (1). This photosensitivecomposition may further contain the above-described sensitizing dye.These photosensitive compositions can efficiently initiatephotopolymerization even in the presence of oxygen.

[0081] The bisimidazole compound for use in the present invention is acompound having a group resulting from two imidazole rings beingcombined at any site and specific examples thereof include2,21-bis(4,5′-dimethylimidazole) and2,2′-bis(o-chlorophenyl)-4,4′,5,5′-tetraphenyl-1,2′-biimidazole. Thecompound selected from the stabilizers which can be used in thephotosensitive composition, and the organic borate salt are preferablyused in an amount of from 10 to 200 wt %, more preferably from 20 to 100wt %, based on the photosensitive composition obtained by the optionalcombination thereof.

[0082] The monomer having one or more ethylenically unsaturated bond foruse in the present invention includes a (meth)acrylic acid and an esterthereof and examples thereof include methyl (meth)acrylate, butyl(meth)acrylate, benzyl (meth)acrylate, phenethyl (meth)acrylate,isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-hydoxyethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate,2-hydroxy-3-phenoxypropyl (meth)acrylate, N,N-dimethylaminoethyl(meth)acrylate, glycidyl (meth)acrylate and methacryloyloxyethylisocyanate. A (meth)acrylamide and an N-substitution product thereof,such as N-methyl(meth)acrylamide, N,N-diethyl(meth)acrylamide,N-butoxymethylacrylamide, isobutoxymethylacrylamide, and(meth)acrylamide-2-methylpropanesulfonic acid and a sodium salt thereof,may also be used.

[0083] Other examples of the monomer having one or more ethylenicallyunsaturated bond for use in the present invention include compoundshaving an N-vinylamide structure such as N-vinylacetamide,N-vinylpropionamide and N-vinyl-butanamide; polyhydric alcohol(meth)acrylates which is an ester obtained by the esterification of anunsaturated carboxylic acid or a polycarboxylic acid with a polyhydriccompound, such as phenoxydiethoxy (meth)acrylate, polyethylene glycoldi(meth)acrylate, 1,3-butanediol di(meth)acrylate, neopentyl glycoldi(meth)acrylate, 2,2-bis[4-(meth)acryloyloxypolyethoxyphenyl]propane,hydroxypivalic acid neopentyl glycol di(meth)acrylate, glycerindi(meth)acrylate, glycerin tri(meth)acrylate, trimethylolethane di(meth)acrylate, triethylolpropane di(meth)acrylate, trimethylolpropanetri(meth)acrylate, isocyanuric acid trierythritol tri(meth)acrylate,pentaerythritol di(meth) acrylate, pentaerythritol tri(meth) acrylate,pentaerythritol tetra(meth)acrylate, dipentaerythritoltri(meth)acrylate, dipentaerythritol tetra(meth)acrylate,dipentaerythritol penta(meth)acrylate, dipentaerythritolhexa(meth)acrylate, and compounds represented by formulae (4) and (5)where n=1 to 9; epoxy (meth)acrylates; and urethane (meth)acrylatesobtained by the reaction with (meth)acryloyloxy isocyanate.

H₂C═C(CH₃)CO—(OCH₂CH₂)_(n)—O—CO—C(CH₃)═CH₂  (4)

[0084] (wherein n is an integer of from 1 to 9);

H₂C═CHCO—(OCH₂CH₂)_(n)—O—CO—CH═CH₂  (5)

[0085] (wherein n is an integer of from 1 to 9).

[0086] The term “(meth)acryl” as used herein means “methacryl” and“acryl”.

[0087] The compound having an ethylenically unsaturated bond for use ina polymerizable composition comprising any combination of an organicborate salt and the stabilizer is added in an amount of from 1 to 5,000parts by weight, preferably from 30 to 2,000 parts by weight, per 1 partby weight of the photosensitive composition. Even when two or more ofthe compound having one or more ethylenically unsaturated bond areadded, the stabilizer of the present invention exerts the effect toincrease the heat stability and in turn, the polymerizable compositionexhibits high sensitivity even in the presence of oxygen. Furthermore,the stabilizer can be used in a composition containing an organic boratesalt, other than the polymerizable composition of the present invention.

[0088] The high molecular polymer for use in the present invention isdescribed below. The high molecular polymer is preferably a linearpolymer containing one or more monomer selected from (meth)acrylic acid,(meth)acrylic ester, N-vinylamide, (meth)acrylamide, N-substituted(meth)acrylamide, N-disubstituted (meth)acrylamide, styrene,alkyl-substituted styrene, chloromethylstyrene, vinylphenol andalkyl-substituted vinylphenol, and having a molecular weight of from1,000 to 500,000, preferably from 5,000 to 100,000. By adjusting theacid value of this high molecular polymer to be 5 mgKOH/g or less, ahigh molecular polymer insoluble in an alkaline aqueous solution can beobtained. On the other hand, by adjusting the acid value to be from 20to 800 mgKOH/g, preferably from 30 to 500 mgKOH/g, a high molecularpolymer soluble in an alkaline aqueous solution can be obtained.

[0089] In the case when the polymerizable composition is used as aresist, the high molecular polymer for use in the present invention isnecessary to dissolve in a solvent at the development and preferablycomprises a monomer having only one polymerizable group. Examples of themonomer used herein include (meth)acrylic acid, methyl (meth)acrylate,butyl (meth)acrylate, benzyl (meth)acrylate, phenethyl (meth)acrylate,isobornyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-hydroxyethyl(meth)acrylate, 2-hydroxypropyl (meth)acrylate,2-hydroxy-3-phenoxypropyl (meth)acrylate, N,N-dimethylaminoethyl(meth)acrylate, glycidyl (meth)acrylate, methacryloyloxyethylisocyanate, N-vinylacetamide, (meth)acrylamide,N-methyl(meth)acrylamide, N,N-diethyl(meth)acrylamide,n-butoxymethylacrylamide, isobutoxymethylacrylamide,N-hydroxymethylacrylamide, (meth)acrylamido-2-methylpropanesulfonicacid, N-vinylpyrrolidone, styrene, α-methylstyrene,p-chloromethylstyrene and p-vinylphenol.

[0090] The high molecular polymer of the present invention preferablycomprises a copolymer of a (meth)acrylic acid and a (meth)acrylic esteras a main component. Examples thereof include a methacrylic acid-butylmethacrylate copolymer, a methacrylic acid-benzyl methacrylatecopolymer, an acrylic acid-methyl methacrylate-butyl methacrylatecopolymer, a methacrylic acid-butyl methacrylate-isobornyl methacrylatecopolymer, a methacrylic acid-2-hydroxyethyl methacrylate-butylmethacrylate copolymer, a methacrylic acid-methyl methacrylate-butylmethacrylate-2-hydroxyethyl acrylate-styrene copolymer, a methacrylicacid-butyl methacrylate- glycidyl methacrylate copolymer, a methacrylicacid-butyl methacrylate-cyclohexyl methacrylate-styrene copolymer, amethacrylic acid-butyl methacrylate-styrene copolymer and a methacrylicacid-acrylic acid-methyl methacrylate-butyl methacrylate copolymer. Thecomposition and the compositional ratio of these copolymers are notparticularly limited and copolymers and copolymer mixtures obtained byany combination at any compositional ratio may be used. The highmolecular polymer is added in an amount of from 0.5 to 200 parts byweight, preferably from 1 to 100 parts by weight, based on thephotosensitive composition comprising any combination of an organicborate salt and the stabilizer.

[0091] Examples of the pigment for use in the present invention include,in term of the color index number, C.I. Pigment Yellow 12, 13, 14, 17,20, 24, 55, 83, 86, 93, 109, 110, 117, 125, 137, 139, 147, 148, 153,154, 166 and 168, C.I. Pigment Orange 36, 43, 51, 55, 59 and 61, C.I.Pigment Red 9, 97, 122, 123, 149, 168, 177, 180, 192, 215, 216, 217,220, 223, 224, 226, 227, 228 and 240, C.I. Pigment Violet 19, 23, 29,30, 37, 40 and 50, C.I. Pigment Blue 15, 15:1, 15:4, 15:6, 22, 60 and64, C.I. Pigment Green 7 and 36, C.I. Pigment Brown 23, 25 and 26, andC.I. Pigment Black 7, and further include carbon black, surface resintreated carbon black, titanium black, aniline black, titanium white,talc, alumina and iron oxide.

[0092] The pigment may be dispersed in the polymerizable compositionusing, if desired, an appropriate dispersant. The pigment is used in anamount of from 0.05 to 80 parts by weight, preferably from 1 to 50 partsby weight, based on the polymerizable composition obtained by adding amonomer having one or more ethylenically unsaturated bond to aphotosensitive composition comprising any combination of a compoundhaving one or more nitrogen-containing 5- or 6-membered heterocyclicring having a double bond within the ring or a compound having a thiolgroup represented by formula (3), out of the stabilizers of the presentinvention, and an organic borate salt represented by formula (1). Two ormore of these compounds may be used in combination to attain proper toneand light-shielding ratio and even in this case, the polymerizablecomposition of the present invention exhibits high sensitivity.

[0093] The polymerizable composition obtained by adding a compoundhaving one or more ethylenically unsaturated bond to the photosensitivecomposition comprising an organic borate salt, the stabilizer and asensitizing dye, the polymerizable composition further containing a highmolecular polymer, and the polymerizable composition still furthercontaining a pigment each may use a solvent according to the use end.

[0094] Examples of the solvent include cyclohexane, isophorone,diethylene glycol dimethyl ether, ethylene glycol diethyl ether,tetrahydrofuran, xylene, ethylbenzene, ethyl cellosolve, butylcellosolve, methyl cellosolve acetate, ethyl cellosolve acetate,acetone, cyclohexanone, methyl ethyl ketone, methyl isobutyl ketone,methyl-n-amyl ketone, diethylene glycol monomethyl ether, diethyleneglycol monoethyl ether, diethylene glycol dimethyl ether, propyleneglycol monomethyl ether acetate, ethyl acetate, isoamyl acetate, ethyllactate and dichloroethane. These solvents may be used individually orin combination of two or more thereof. The solvent is added in an amountof from 0.05 to 100 parts by weight based on the polymerizablecomposition. The solvent is preferably removed by evaporation in advanceof the polymerization.

[0095] The polymerizable composition is coated on a substrate, thesolvent is evaporated, and the resist film obtained is irradiated withlight through a pattern mask. As a result, the photosensitivecomposition exposed to light is activated to generate radicals andthereby the ethylenically unsaturated bonds cause chain reaction toconnect with each other, thus, the polymerization proceeds. Thepolymerization does not proceed in the area not exposed to light and byremoving the area using an excess of an appropriate solvent such asmethyl alcohol, ethyl alcohol, isopropyl alcohol, cyclohexane,isophorone, cellosolve acetate, diethylene glycol dimethyl ether,ethylene glycol diethyl ether, xylene, ethylbenzene, ethyl cellosolve,butyl cellosolve, acetone, cyclohexanone, methyl ethyl ketone, methylisobutyl ketone, methyl-n-amyl ketone, propylene glycol monomethyl etheracetate, ethyl acetate, isoamyl acetate, ethyl lactate ordichloromethane, the area exposed to light remains on the substrate anda colored pattern in accordance with the pigment added can be formed.

[0096] At this time, when the high molecular polymer contained in thepolymerizable composition has a high acid value (20 to 800 mgKOH/g), theunexposed area can be removed using the above-described organic solventand additionally an alkaline aqueous solution (pH=9 to 12). The alkalineaqueous solution which can be used is an aqueous solution containing oneor more of sodium hydroxide, potassium hydroxide, sodium carbonate,potassium carbonate and trialkylamine.

[0097] In this case, the photosensitive composition comprising acompound having one or more nitrogen-containing 5- or 6-memberedheterocyclic ring having a double bond within the ring or a compoundhaving a thiol group represented by formula (3) and an organic boratesalt represented by formula (1) of the present invention has goodphotopolymerization initiating ability even in the presence of oxygenand accordingly, irrespective of the presence or absence of anoxygen-blocking overcoat on the film of the polymerizable compositioncoated on a substrate, the same colored pattern can be formed.

[0098] The present invention is described in greater detail below byreferring to the Examples and Comparative Examples, however, the presentinvention should not be construed as being limited thereto as long asthe scope of the present invention is persisted.

[0099] The quantitative determination of the organic borate salt wasperformed using a high performance liquid chromatography (HPLC) (column:SHODEX C8-5B; mobile phase: a 85:15 mixture of acetonitrile containing 4mM of tetra-octylammoniurm bromide:water; detector: SPD-l1AV,manufactured by Shimadzu Seisakusho).

[0100] The effect of the stabilizers of the present invention wasverified by Examples 1 to 8 and Comparative Examples 1 to 5.

EXAMPLE 1

[0101] A composition was prepared by dissolving 0.1 part by weight ofmercaptobenzothiazole as the stabilizer of the present invention and 3parts by weight of tetrabutylammonium n-butyltri(4-methylnaphthyl)borate as the organic borate salt in 100 parts by weight ofγ-butyrolactone. The composition obtained was kept at 90° C. for 5 hoursand then, the residual ratio of the organic borate salt was 98%.

EXAMPLE 2

[0102] A composition was prepared by dissolving 0.1 part by weight of3-amino-1,2,4-triazole as the stabilizer of the present invention and 3parts by weight of tetrabutylammonium n-butyltrinaphthyl borate as theorganic borate salt in 100 parts by weight of γ-butyrolactone. Thecomposition obtained was kept at 90° C. for 5 hours and then, theresidual ratio of the organic borate salt was 99%.

EXAMPLE 3

[0103] A composition was prepared by dissolving 0.2 part by weight of2,4,6-triamino-1,3,5-triazine as the stabilizer of the present inventionand 3 parts by weight of1,1,5,5-tetrakis(p-diethylaminophenyl)-2,4-pentadieniliumn-butyl-triphenyl borate as the organic borate salt in 100 parts byweight of γ-butyrolactone. The composition obtained was kept at 90° C.for 5 hours and then, the residual ratio of the organic borate salt was90%.

EXAMPLE 4

[0104] A photosensitive composition of the present invention wasprepared by dissolving 0.1 part by weight ofN,N,N′,N′-tetramethylethylenediamine as the stabilizer of the presentinvention, 3 parts by weight of tetrabutylammoniuirn-butyltri(p-ethoxyphenyl) borate as the organic borate salt, and 0.5part by weight of Crystal Violet as the sensitizing dye in 100 parts byweight of γ-butyrolactone. The composition obtained was kept at 90° C.for 5 hours and then, the residual ratio of the organic borate salt was82%.

EXAMPLE 5

[0105] A polymerizable composition of the present invention was preparedby adding 100 parts by weight of epoxy acrylate having an acidity of 70(mgKOH/g), 2 parts by weight of tetrabutylammonium n-butyltrinaphthylborate and 0.15 part by weight of mercaptobenzimidazole as thestabilizer of the present invention to 100 parts by weight of ethylacetate. The composition obtained was stored at 55° C. for 48 hours andthen, the residual ratio of the organic borate salt was measured andfound to be 72%.

EXAMPLE 6

[0106] A polymerizable composition of the present invention was preparedby adding 100 parts by weight of epoxy acrylate having an acidity of 70(mgKOH/g), 2 parts by weight of tetrabutylammoniumbutyltri(4-methylnaphthyl) borate and 0.15 part by weight ofdimercaptothiadiazole as the stabilizer of the present invention to 100parts by weight of ethyl acetate. The composition obtained was stored at55° C. for 48 hours and then, the residual ratio of the organic boratesalt was 86%.

EXAMPLE 7

[0107] A polymerizable composition of the present invention was preparedby mixing 100 parts by weight of propylene glycol monomethyl acetate,100 parts by weight of an acrylate monomer having an acidity of 60(mgKOH/g), 2 parts by weight of tetrabutylammonium butyltrinaphthylborate, 1 part by weight of Basic Red 1 and 0.5 part by weight of2,6dimethylolpyridine as the stabilizer of the present invention.

[0108] For determining the sensitivity of the polymerizable compositionprepared, the polymerizable composition was coated on a polyethyleneterephthalate film to have a dry thickness of 5 μm under the conditionof shielding light., and then the solvent was evaporated at roomtemperature. The exposure amount necessary for polymerizing and curingthe polymerizable composition of the present invention was measuredusing a Deep UV lamp as the light source and the energy obtained wasused as the index for the sensitivity (the smaller the value, the higherthe sensitivity). The polymerizable composition prepared above hadsensitivity of 5.6 mJ/cm². This polymerizable composition was stored ina dark place at 80° C. for 3 hours and then, the residual ratio oftetrabutylammonium butyltrinaphthyl borate as the organic borate saltwas 95%. The sensitivity determined in the same manner as above was 5.6mJ/cm².

EXAMPLE 8

[0109] A polymerizable composition of the present invention was preparedby mixing 100 parts by weight of methylene chloride, 100 parts by weightof pentaerythritol tetraacrylate, 100 parts by weight of an epoxyacrylate having an acidity of 70 (mgKOH/g)f 1 part by weight oftetrabutylammonium butyltri(6-methoxy-β-naphthyl) borate, 1 part byweight of Victoria Pure Blue BOH and 2 parts by weight ofmercaptopyrimidine as the stabilizer of the present invention.

[0110] The sensitivity of the polymerizable composition prepared wasdetermined in the same manner as in Example 7 and found to be 5.6mJ/cm². This polymerizable composition was stored in a dark place at 80°C. for 3 hours and then, the residual ratio of tetrabutylammoniumbutyltri(6-methoxy-β-naphthyl) borate as the organic borate salt was98%. The sensitivity determined in the same manner as above was 5.6mJ/cm².

COMPARATIVE EXAMPLE 1

[0111] A composition prepared in the same manner as in Example 1 exceptfor excluding the stabilizer of the composition was evaluated in thesame manner as in Example 1. After the storage at 90° C. for 5 hours,the residual ratio of tetrabutylammonium n-butyltri(4-methylnaphthyl)borate was 45%.

COMPARATIVE EXAMPLE 2

[0112] A composition prepared in the same manner as in Example 2 exceptfor excluding the stabilizer of the composition was stored at 90° C. for5 hours. Then, the residual ratio of tetrabutylammoniumn-butyltrinaphthyl borate was 55%.

COMPARATIVE EXAMPLE 3

[0113] A composition prepared in the same manner as in Example 3 exceptfor excluding the stabilizer of the composition was stored at 90° C. for5 hours. Then, the residual ratio of1,1,5,5-tetrakis(p-diethylaminophenyl)-2,4-pentadieniliumn-butyltriphenyl borate was 50%.

COMPARATIVE EXAMPLE 4

[0114] A composition prepared in the same manner as in Example 4 exceptfor excluding the stabilizer of the composition was stored at 90° C. for5 hours. Then, the residual ratio of tetrabutylammoniumn-butyltri(p-ethoxyphenyl) borate was 55%.

COMPARATIVE EXAMPLE 5

[0115] A polymerizable composition was prepared in the same manner as inExample 7 except for excluding the stabilizer of the polymerizablecomposition. The sensitivity of the polymerizable compositionimmediately after the preparation was determined in the same manner asin Example 7 and then, the exposure amount necessary for curing thecomposition was 5.6 mJ/cm². After storage at 80° C. for 3 hours, theresidual ratio of tetrabutylammonium butyltrinaphthyl borate was 50% andthe sensitivity was 56.2 mJ/cm².

[0116] It is apparent from the comparison between Example 1 andComparative Example 1, Example 2 and Comparative Example 2, Example 3and Comparative Example 3, and Example 4 and Comparative Example 4,respectively, that the organic borate salt is prevented from thermaldecomposition by the stabilizer of the present invention. Furthermore,as is apparent from the comparison between Example 7 and ComparativeExample 5, the decomposition is prevented while maintaining thesensitivity during the storage by the stabilizer of the presentinvention.

[0117] The effect of the presence or absence of oxygen on thephotocurability of the polymerizable composition of the presentinvention is described by referring to Examples 9, 10, 14 and 15 andComparative Example 6. In these Examples, the polymerizable compositionprepared is called a resist for the sake of convenience. In theseExamples, an alkali development-type black resist was formed by theproduction method of a black matrix for color liquid crystal displays,particularly by the commonly employed pigment dispersion method in whichphotopolymerization of a thin film in the presence of oxygen is requiredin view of simplification of the process.

[0118] A synthesis example of a high molecular polymer soluble in analkaline aqueous solution, which is a high molecular polymer used inthese Examples, is described below. In the following, unless otherwiseindicated, the “part” is “part by weight”.

[0119] Synthesis Example of High Molecular Polymer

[0120] A mixed solution containing 350 parts of cyclohexanone, 26.2parts of styrene, 23.3 parts of 2-hydroxyethyl acrylate, 35 parts ofmethacrylic acid, 20.5 parts of methyl methacrylate and 70 parts ofbutyl methacrylate was heated at 90° C. and reacted for 3 hours whilegradually adding dropwise thereto a dissolution product of 290 parts ofcyclohexanone, 26.2 parts of styrene, 23.3 parts of 2-hydroxyethylacrylate, 35 parts of methacrylic acid, 20.5 parts of methylmethacrylate, 70 parts of butyl methacrylate and 1.75 parts ofazobisisobutyronitrile. Thereto, 10 parts of cyclohexanone havingdissolved therein 0.70 part of azobisisobutyronitrile was added and themixed solution was reacted for another one hour. A part of the resultinghigh molecular polymer solution was dried by heating in vacuum at 90° C.for 60 minutes and the non-volatilized content measured. Thenon-volatile content was adjusted to 25% by adding cyclohexanone toobtain a high molecular polymer solution. This polymer had an averagemolecular weight of about 50,000 and an acid value of 120 mgKOH/g.

[0121] Preparation of Black Resist High molecular polymer solution  34parts Carbon black 8.0 parts (FW200, produced by Degssa KK) Dispersant(HOMOGENOL L-18, 0.8 part produced by Kao Corporation) Cyclohexanone  29parts

[0122] These components were mixed, dispersed in a bead mill for 360minutes and filtered through a 0.7-μm filter to prepare a black pigmentdispersion solution. Thereafter, the following components werethoroughly mixed in a container. Black pigment dispersion solution   56parts Trimethylolpropane triacrylate 4.15 parts Compound A 1.00 partCompound B 0.20 part Compound C 1.00 part Cyclohexanone 37.3 parts

[0123] The resulting mixed solution was filtered through a 1.0-μm filterto prepare Black Resist 1 having a non-volatile content of about 20%.

[0124] In the Examples, a tetraalkylammonium organic borate salt asCompound A, a sensitizing dye as Compound B and an organic compoundcontaining thiol as Compound C were combined as follows.

EXAMPLE 9

[0125] Compound A: tetrabutylammonium butyltrinaphthyl borate

[0126] Compound B: 3-Carboethoxy-7- (diethylamino) coumarin

[0127] Compound C: 2-mercaptobenzoxazole

EXAMPLE 10

[0128] Compound A: tetrabutylammonium methyltrinaphthyl borate

[0129] Compound B: Basic Yellow 21

[0130] Compound C: mercaptobenzothiazole

[0131] Bisimidazole Compound:

[0132] 2,2′-bis (o-chlorophenyl)-4,4′,5,5′-tetraphenyl-1,2′-bilmidazole

EXAMPLE 11

[0133] Compound A: tetrabutylammonium butyltri (4-tert-butylphenyl)borate

[0134] Compound B: Basic Yellow 21

[0135] Compound C: 2-mercaptothiazoline

EXAMPLE 12

[0136] Compound A: tetrabutylammonium butyltri (4-methylnaphthyl) borate

[0137] Compound B: Basic Yellow 13

[0138] Compound C: 5-methyl-1, 3, 4-thiadiazole-2-thiol

EXAMPLE 13

[0139] Compound A: tetrabutylammonium methyltri (4-methylnaphthyl)borate

[0140] Compound B: Basic Yellow 21

[0141] Compound C: 3-mercapto-4-methyl-4H-1,2,4-triazole

[0142] Each resist solution was spin-coated on a clean glass platehaving a thickness of 1 mm and a size of 10 cm×10 cm and dried at roomtemperature for 30 minutes and then at 700° for 20 minutes to form a 2μm-thick resist film. The glass plate having coated thereon the resistfilm was designated as Glass Plate (A). For determining the spectralsensitivity, Glass Plate (A) was set in an irradiation spectroscope(Model JASCO CT-25CP, manufactured by Nippon Bunko KK) and exposed. Thelight source used was a 150W xenon lamp. After the exposure, the resistfilm was developed, thoroughly washed with water and dried to obtain aspectral image. The maximum step number where the resist film was notdissolved by the development with i-ray (365 nm), h-ray (405 nm) org-ray (436 nm) in respective Examples, is shown in Table 1. The largerthe step number, the higher the sensitivity.

EXAMPLE 14

[0143] The resist obtained in Example 9 was coated on a glass substratein the same manner and dried at room temperature for 30 minutes and thenat 70° C. for 20 minutes. On the resist coating formed, a 5% aqueoussolution of polyvinyl alcohol (polymerization degree: about 1,000,saponification degree: about 98%) was coated by a spin coater to have adry thickness of from 1.2 to 1.3 μm and dried at 70° C. for 20 minutesin a hot air oven to form an oxygen-blocking film. Thereafter, thespectral sensitivity was measured in the same manner as in Example 9.

COMPARATIVE EXAMPLE 6

[0144] A resist was prepared in the same manner as in Example 9 exceptthat mercaptobenzoxazole used as Compound C in the resist composition ofExample 9 was not added. The resist obtained was coated and dried on aglass substrate in the same manner as in Example 9 to prepare a resistfilm. The resist film formed was measured on the spectral sensitivity inthe same manner as in Example 9.

EXAMPLE 15

[0145] A resist film with an oxygen-blocking film was formed on a glasssubstrate using the resist obtained in Example 10 in the same manner asin Example 14 and the spectral sensitivity thereof was measured in thesame manner as in Example 9. TABLE 1 Spectral Sensitivity g h i Example9 4 6 6 Example 10 9 9 6 Example 11 6 6 4 Example 12 8 7 6 Example 1311  11  8 Example 14 4 6 6 Comparative 2 3 3 Example 6 Example 15 9 9 6

[0146] As apparent from the results in Table 1, comparison betweenExample 9 and Comparative Example 6 reveals that the sensitivity lowerswhen the organic compound having a thiol group according to the presentinvention is not added, comparison between Example 9 and Example 14reveals that sensitivity equal to that in the case of an oxygen-blockingfilm being formed is obtained by adding the organic compound having athiol group, and comparison between Example 10 and Example 15 revealsthat the sensitivity is not lowered as compared with the case of anoxygen-blocking film being formed and hence, the polymerizablecomposition of the present invention exhibits high sensitivity even inthe presence of oxygen.

[0147] By adding the stabilizer of the present invention to an organicborate salt, the organic borate salt can be remarkably improved in theheat stability and aging stability.

[0148] Also in the photosensitive composition of the present inventioncomprising the stabilizer of the present invention, an organic boratesalt and a sensitizing dye, the organic borate salt can be remarkablyimproved in the heat stability and aging stability.

[0149] Furthermore, in the polymerizable composition comprising thephotosensitive composition of the present invention having added theretoa monomer having an ethylenically unsaturated bond, the organic boratesalt can be remarkably improved in the heat stability and agingstability and moreover, the polymerizability of the composition is notimpaired.

[0150] The photosensitive composition of the present invention exhibitshigh sensitivity even in the presence of oxygen and the polymerizablecomposition obtained by adding a monomer having an ethylenicallyunsaturated bond and a high molecular polymer to the photosensitivecomposition efficiently undergoes polymerization even in the presence ofoxygen.

[0151] While the invention has been described in detail and withreference to specific embodiments thereof, it will be apparent to oneskilled in the art that various changes and modifications can be madetherein without departing from the spirit and scope thereof.

What is claimed is:
 1. A stabilizer for thermally stabilizing an organicborate salt represented by formula (1), comprising a compound having oneor two nitrogen-containing 5- or 6-membered heterocyclic ring having adouble bond within the ring, a compound having a primary, secondary ortertiary amino group, or a compound having a thiol group:

(wherein R₁, R₂, R₃ and R₄ each independently represents an alkyl group,an aryl group, an allyl group, an aralkyl group, an alkenyl group, analkynyl group, an alkoxy group, a silyl group, an alicyclic group, aheterocyclic group, a hygrogen atom or a halogen atom, and Z⁺ representsa quaternary ammonium cation, a quaternary pyridinium cation, aquaternary quinolinium cation, a phosphonium cation, a sulfonium cation,an oxosulfonium cation, an oxonium cation, an iodonium cation, a metalcation or a cationic dye having absorption in the ultraviolet and/orvisible ray region).
 2. The stabilizer for thermally stabilizing anorganic borate salt as claimed in claim 1 , wherein, in formula (1), R₁,R₂, R₃ and R₄ each.independently represents an alkyl group, an arylgroup, an allyl group, an aralkyl group, an alkenyl group, an alkynylgroup, an alkoxy group, a siyl group, a heterocyclic group, a hydrogenatom or a halogen atom, and Z⁺ represents a quaternary ammonium cation,a quaternary pyridinium cation, a quaternary quinolinium cation, aphosphonium cation, a sulfonium cation, an oxonium cation, an iodoniumcation, a metal cation or a cationic dye having absorption in theultraviolet and/or visible ray region).
 3. The stabilizer for thermallystabilizing an organic borate salt as claimed in claim 1 , wherein thecompound having one or two nitrogen-containing 5- or 6memberedheterocyclic ring having a double bond within the ring is a compoundhaving one or more heterocyclic ring selected from triazole, pyridine,pyrimidine, pyrazole, piperazine, tetrazole, acridine, adenine,benzothiazole, triazine, thiadiazole, imidazole, benzimidazole,thiazoline, indoline and imidazoline.
 4. The stabilizer for thermallystabilizing an organic borate salt as claimed in claim 1 , wherein thecompound having a primary, secondary or tertiary amino group is an aminerepresented by formula (2): R₅R₆R₇N  (2) (wherein R₅, R₆ and R₇ eachindependently represents hydrogen, an alkyl group, an aryl group, anallyl group, an aralkyl group, an alkenyl group, an alkynyl group, analicyclic group or a heterocyclic group, provided that at least one ofR₅, R₆ and R₇ is not hydrogen; two or three of R₅, R₆ and R₇ may becombined to form a cyclic structure).
 5. The stabilizer for thermallystabilizing an organic borate salt as claimed in claim 1 , wherein thecompound having a thiol group is a thiol represented by formula (3):R₈—SX  (3) (wherein R₈ represents an alkyl group, an aryl group, anaralkyl group, an alkenyl group, an alkynyl group, an alicyclic group ora heterocyclic group, and X represents sodium or a hydrogen atom).
 6. Aphotosensitive composition comprising the stabilizer described in claim1 and an organic borate salt represented by formula (1):

(wherein R₁, R₂, R₃ and R₄ each independently represents an alkyl group,an aryl group, an allyl group, an aralkyl group, an alkenyl group, analkynyl group, an alkoxy group, a silyl group, an alicyclic group, aheterocyclic group, a hygrogen atom or a halogen atom, and Z⁺ representsa quaternary ammonium cation, a quaternary pyridinium cation, aquaternary quinolinium cation, a phosphonium cation, a sulfonium cation,an oxosulfonium cation, an oxonium cation, an iodonium cation, a metalcation or a cationic dye having absorption in the ultraviolet and/orvisible ray region).
 7. The photosensitive composition as claimed inclaim 6 , wherein, in formula (1), R₁, R₂, R₃ and R₄ each independentlyrepresents an alkyl group, an aryl group, an allyl group, an aralkylgroup, an alkenyl group, an alkynyl group, an alkoxy group, a silylgroup, a heterocyclic group, a hydrogen atom or a halogen atom, and Z⁺represents a quaternary ammonium cation, a quaternary pyridinium cation,a quaternary quinolinium cation, a phosphonium cation, a sulfoniumcation, an oxonium cation, an iodonium cation, a metal cation or acationic dye having absorption in the ultraviolet and/or visible rayregion.
 8. The photosensitive composition as claimed in claim 6 ,further comprising a sensitizing dye.
 9. The photosensitive compositionas claimed in claim 6 , wherein the stabilizer is a compound having oneor two nitrogen-containing 5- or 6-membered heterocyclic ring having adouble bond within the ring or a compound having a thiol group.
 10. Thephotosensitive composition as claimed in claim 9 , wherein thestabilizer is at least one selected from mercaptoimidazole,mercaptobenzimidazole, mercaptobenzothiazole, triazinetrithiol,mercaptotriazole, mercaptothiazoline, mercaptothiadiazole andmercaptotetrazole.
 11. The photosensitive composition as claimed inclaim 9 , which further contains a bisimidazole compound.
 12. Apolymerizable composition capable of polymerization by light or heat,comprising the photosensitive composition described in claim 6 havingadded thereto at least one monomer having one or more ethylenicallyunsaturated bond.
 13. The polymerizable composition as claimed in claim12 , further comprising a high molecular polymer.
 14. The polymerizablecomposition as claimed in claim 13 , further comprising a pigment. 15.The polymerizable composition as claimed in claim 13, wherein the highmolecular polymer has an acid value of from 20 to 800 mgKOH/g.
 16. Acolored pattern formed on a substrate using a polymerizable compositiondescribed in claim 12 .